The present invention relates to a polymer electrolyte membrane and, more particularly, to a polymer electrolyte membrane for SF6 separation. The present invention relates to a polymer electrolyte membrane, which may be manufactured in any form, such as a hollow fiber type, a planar type, etc., and may exhibit superior SF6 separation efficiency even without the use of an additional complicated module or device.
SF6 is a typical electrical insulating material, and is used in the cleaning process upon manufacturing a semiconductor wafer or an LCD panel. However, SF6 is known to have an effect on global warming as high as about 23900 times that of carbon dioxide. SF6, which remains stably present in the air without decomposing for 3200 years, was identified as one of six materials having a high global warming index in the Kyoto climate change convention, 1997.
Methods of treating SF6 used in various industrial processes include the decomposition of SF6 and the separation and recycling of SF6.
Since SF6 is very stable, the decomposition processes thereof include plasma, electrical discharge, a spark method, etc., requiring high energy, and in the decomposition process, byproducts having high toxicity and corrosivity, such as S2F10, SF4, and HF, are undesirably generated.
In consideration of continuous increases in the price of SF6, as well as problems with SF6 decomposition techniques, techniques for separating and recovering SF6 that enable the recycling of SF6 are receiving attention in place of decomposition techniques thereof. The techniques for separating and recovering SF6 typically include cryogenics, PSA (Pressure Swing Adsorption), the use of a membrane, etc. Among these processes, the use of a membrane is adopted to recover SF6 in the present invention.
Conventional patents related to techniques for separating and recovering SF6 using a membrane are described below.
Korean Patent No. 10-1556707 discloses a membrane technique for SF6 separation, involving coating a support with a coating solution, resulting from dissolving cellulose acetate and polyethylene glycol in a coating solvent mixture comprising acetic acid and isopropanol (IPA).
Korean Patent No. 10-1420767 discloses a technique for an SF6 separation device using a hollow fiber membrane.
Korean Patent Nos. 10-1420082 and 10-1410914 disclose a technique for separating SF6 that is generated during the production of a semiconductor.
Conventional SF6 separation techniques using a membrane are mainly directed to membrane modules, rather than the development of membrane materials. The fabrication of modules having a complicated structure suffers from high costs and difficulty in manufacturing large-scale devices. Furthermore, SF6 separation efficiency is still unsatisfactory.